text: Somewhat like the parent amines, imines are mildly basic and reversibly protonate to give iminium salts: 
  :RC=NR  +  H     [RC=NHR]
  Alternatively, primary imines are sufficiently acidic to allow N-alkylation, as illustrated with benzophenone imine:
  :(CH)C=NH  +  CHLi  →  (CH)C=NLi  +  CH
  :(CH)C=NLi  +  CHI  →  (CH)C=NCH  +  LiI